Being Different Helps.....

Being Different Helps..............

You could make a GPS product, but there are too many. You could make a game console, but again there are too many. So how do you pick a popular segment, and yet make a product that wins? By being different! For example, adding an anti-theft component to a GPS product, a touch-free scanner to an access control system, or a charger that draws power from a cooking pot might kindle buyers’ curiosity. Let us look at a couple of such products that bring an interesting twist to their respective segment  

1.   Capturing images in the wild—with no power.

2.    A tool to help golfers practice

3.    Preventing new-borns’ brain damage,  the low-cost way.

4.   Charge your devices using a cooking pot

5.   Cloud-based ridership tracking

6.   Nostalgic experience for gamers.

Capturing images in the wild—with no power

 
Suppose you are camping or trekking and your camera runs out of power just when you are witnessing a breath-taking sunset that you want to capture? Indeed, there are several devices today that provide portable power—there are solar chargers, kinetic chargers and other such innovative options cropping up, but Superheadz’s Sun & Cloud offers a much better solution. Japanese company Superheadz has come up with a hand-cranked digital camera that works on self-generated power.
Inside: Sun & Cloud is capable of shooting both videos and stills, and has most of the features of a normal digital camera. What makes it unique is that it does not rely on batteries or grid power, and can be charged using kinetic energy from a hand crank. It is also equipped with a solar panel for sunny days, and is capable of USB charging when available. Sun & Cloud comes with 15 built-in filters,a three megapixel lens and three shooting modes (normal, portrait and macro). It has a high-power LED light for night shots, a built-in microphone for audio recording, and support for micro SD and micro SDHC cards. Just because it has a hand crank, do not assume that is will be huge and heavy—it measures 15.2×15.2×20.3 cm3 and weighs just 200 gm.
A tool to help golfers practice

 
Motion-sensor-based sports training aids are becoming popular today, and there are such tools for golf practice too. However, golfers grudge that these tools help only in the full swing and are not effective with smaller strokes. Putting, however, is very important and experts often call it a game within the game. It accounts for over 40 per cent of a golfer’s strokes. So it is important that a player is good at putting too. Here is a golf motion analyser that is small and light enough to fitinto the corner of the putter’s grip. With extremely capable sensors and a smart app, 3BaysGSA PUTT can analyse key aspects of putting strokes very well indeed.
Inside: 3BaysGSA PUTT is a tiny device made of light plastic-like material. It uses a motion-sensing engine with 9-axis sensors that can detect, capture and digitise even the subtlest of movements. The device is to be fittedon the putter, and paired to your mobile phone using a Bluetooth. Thereafter, the sensor information is transferred to your mobile phone and analysed using an intelligent algorithm. Clear graphic representations of the stroke path, along with several key statistics are displayed on your device, and stored for later analysis as well. The small device is chargeable, and works for around three to four hours on each charge.
Preventing new-borns’ brain damage,  the low-cost way

 
Sometimes, conditions like umbilical cord entanglement and anaemia can deprive babies of oxygen just before birth, causing brain damage and cerebral palsy. The best way to prevent this is ‘therapeutic hypothermia’ or cooling of the baby for an extended period of time, under safe conditions. Well-equipped hospitals have incubator-like cooling devices, which maintain a specific temperature till the baby recovers, bt these cost around $12,000 and are not affordable by all.
Recently, students at John Hopkins University, Maryland, USA, have developed a low-cost device called Cooling Cure, for reducing the temperature of babies at a cost of just $40. Inside: The Cooling Cure system can reduce a new-born’s temperature by about six degrees for three consecutive days. The cooler is made of a clay pot and a plastic-lined basket, separated by a layer of sand and urea-based powder, similar to the cooling powder used commonly in instant cold-packs. When water is added to the sand and powder mixture, the resulting chemical reaction draws heat away from the upper basket, which cradles the child. A battery-powered microprocessor and sensors track the child’s internal and skin temperatures. A green light indicates proper temperature, red warns of too high temperature and blue indicates too low temperature. The care-giver can accordingly add water to the sand to increase cooling, or lift the child away for a while if the temperature is too low.

Charge your devices using a cooking pot

 
When you are camping in the middle of nowhere, and want to charge your phone, you could draw out the PowerPot and start cooking a stew. Voila, your devices will get charged. PowerPot is a cooking utensil that can convert changing temperatures (of any water-based food inside it) into electricity. It can be used for wildlife tours, medical camps or rescue missions—any place where you would be cooking but do not have electricity. The basic model costs $149 but you could upgrade it with adaptors, lights, batteries, water purifiers,light-weight stove and other accessories. Inside: The PowerPot uses a thermoelectric differential transducer to harness the power of changing water temperatures within the pot. The more the temperature difference, the more electricity is produced. There is a built-in regulator, which outputs 5 V (USB standard) and up to 1000 mA of current, which is enough to charge smartphones, MP3 players, radio, GPS devices, lights, water-purifiersand other such devices. It is almost like charging off a normal outlet at home. Simply fill te pot with fluid, plug-in the regulating cable and close the handles to gude it away from the heat. Place the pot on any heat source and start cooking. Within seconds, a green indicator lights up and you can start charging devices. The pot is waterproof, fire-resistant and light-weight. It doesnot rely on sunlight, so it can be used any time. There are no moving parts or batteries, and since the thermoelectric technology is built into the bottom of the pot it can produce electricity from a wide variety of heat sources. The only condition is that water must be used for cooking, since it acts as a heat-sink to maintain the temperature difference required to produce thermal electricity.

Cloud-based ridership tracking 

 
Kidtrack is a biometric ridership monitoring system that helps keep track of who is riding on which bus. The cloud-based system can be effectively used by schools, offices, tours, parents and othr caregivers to make sure people get on the right bus, go to the right places and get off at the right points. Parents can breathe easy when they send their kids to school. It will also be very useful in emergency evacuations, route diversions and such situations. Inside: Developed by T&W Operations Inc., Kidtrack makes use of Fujitsu’s PalmEntry physical access control system, which is a secure, contactless, biometric access control solution that positively authenticates the identity of an individual. PalmEntry scanners are installed near the doors of buses. When kids board the bus, they simply place their palm in front of the scanner, which recognises individuals using the unique vein pattern on their palm. A confirmatorybeep sounds, and the scanned information is pushed to the cloud wirelessly, to be accessed by the authorised users and applications.

PalmEntry relies on Fujitsu’s PalmSecure biometric palm vein sensors, which use near-infrared light to capture a user’s palm vein pattern, generating a unique biometric template that is matched against the palm vein patterns of pre-registered users. Unlike other readers, PalmSecure-based devices do not come in contact with the skin, making the technology extremely hygienic, non-intrusive and independent of factors such as skin types and conditions.

Nostalgic experience for gamers

 
Like music aficionados,gamers also like to relive old memories. There is a rising crowd of retro-gamers who have a penchant for old games. Some have even preserved their old cartridges and controllers, and are waiting for a chance to use them. Hyperkin offers a way out with its range of retro-gaming consoles. The new Hyperkin RetroN 5, for example, supports games from seven vintage systems.
Inside: The RetroN 5 console has reverse-engineered hardware, which is nearly two decades old, and allows games from seven systems to be played. It plays original game cartridges and will also support original controllers. It is not a slack on state-of-the-art features either, as is proven by its high-definition multimedia inerface (HDMI) capability, which can upscale games up to 720 p, allowing classic games to be played on HDTVs. Audio-video ports are also present, in case you want to use your old cathode ray tube (CRT) TV. There are five cartridge slots on board that can handle NES, SNES, Geesis, Famicom, Game Boy Advance, Game Boy Color and the original Game Boy game cartridges. RetroN 5 has two Bluetooth controllers and six controller ports on the console to use old pads. You can save your game to the console, to the cartridge, or to some kind of removable storage like an SD card. You can save and resume at any point in the game, speed through slow parts (overclocking), configure conrollers and pick what to play (using a PS3 like interface). The console is likely to be priced around $100. 

"artificial skin" that senses touch, humidity and temperature....

Breakthrough could lead to "artificial skin" that senses touch, humidity and temperature

Using tiny gold particles and a kind of resin, a team of scientists at the Technion-Israel Institute of Technology has discovered how to make a new kind of flexible sensor that one day could be integrated into electronic skin, or e-skin. If scientists learn how to attach e-skin to prosthetic limbs, people with amputations might once again be able to feel changes in their environments. The findings appear in the June issue of ACS Applied Materials & Interfaces.

The secret lies in the sensor's ability to detect three kinds of data simultaneously. While current kinds of e-skin detect only touch, the Technion team's invention "can simultaneously sense touch, humidity, and temperature, as real skin can do," says research team leader Professor Hossam Haick. Additionally, the new system "is at least 10 times more sensitive in touch than the currently existing touch-based e-skin systems."

Researchers have long been interested in flexible sensors, but have had trouble adapting them for real-world use. To make its way into mainstream society, a flexible sensor would have to run on low voltage (so it would be compatible with the batteries in today's portable devices), measure a wide range of pressures, and make more than one measurement at a time, including humidity, temperature, pressure, and the presence of chemicals. In addition, these sensors would also have to be able to be made quickly, easily, and cheaply.

The Technion team's sensor has all of these qualities. The secret is the use of monolayer-capped nanoparticles that are only 5-8 nanometers in diameter. They are made of gold and surrounded by connector molecules called ligands. In fact, "monolayer-capped nanoparticles can be thought of as flowers, where the center of the flower is the gold or metal nanoparticle and the petals are the monolayer of organic ligands that generally

The team discovered that when these nanoparticles are laid on top of a substrate – in this case, made of PET (flexible polyethylene terephthalate), the same plastic found in soda bottles – the resulting compound conducted electricity differently depending on how the substrate was bent. (The bending motion brings some particles closer to others, increasing how quickly electrons can pass between them.) This electrical property means that the sensor can detect a large range of pressures, from tens of milligrams to tens of grams. 


"The sensor is very stable and can be attached to any surface shape while keeping the function stable," says Dr. Nir Peled, Head of the Thoracic Cancer Research and Detection Center at Israel's Sheba Medical Center, who was not involved in the research.


And by varying how thick the substrate is, as well as what it is made of, scientists can modify how sensitive the sensor is. Because these sensors can be customized, they could in the future perform a variety of other tasks, including monitoring strain on bridges and detecting cracks in engines.
"Indeed," says Dr. Peled, "the development of the artificial skin as biosensor by Professor Haick and his team is another breakthrough that puts nanotechnology at the front of the diagnostic era."
The research team also included Meital Segev-Bar and Gregory Shuster, graduate students in the Technion's Russell Berrie Nanotechnology Institute, as well as Avigail Landman and Maayan Nir-Shapira, undergraduate students in the Technion's Chemical Engineering Department. Landman and Nir-Shapira are recipients of this year's Norman and Barbara Seiden Family Prizes For Multidisciplinary Undergraduate Student Projects in Optoelectronics, Microelectronics and Nanosciences.

Surgeons could one day restore lost feeling in humans by using artificial skin that's been augmented with flexible sensors, and a new development from researchers at the Technion-Israel Institute of Technology may bring that closer to reality. The research team has developed a flexible sensor that can detect touch, temperature, and humidity — and can reportedly be built at a low cost. Lead researcher Hossam Haick told the American Technion Society that it is the first artificial skin sensor built with the ability to detect temperature and humidity, and that its touch sensitivity is 10 times greater than any electronic skin that came before it.

Even though it's the first artificial skin sensor to record temperature and humidity, the researchers say that it can sense them quite accurately, reporting back with only a small margin of error for each. The technology is based on gold nanoparticles that are mounted to metal and a flexible plastic. According to the Technion Society, varying the thickness of that plastic can increase or decrease the sensor's overall sensitivity. That setup apparently allows the device to run off of common low-voltage batteries as well — an important trait for what will eventually be a portable sensor. The researchers have already built a prototype of the flexible device, and they believe that it will eventually be adaptable into various types of electronic skin.

3D Transistors: Better Performance at Even Lower Power

3D Transistors: Better Performance at Even Lower Power

 Technology has progressed quite swiftly, since one of the greatest inventions-transistor, paving way for more powerful, cost-effective and energy efficient products. For the first time in history, silicon transistors have entered the third dimension with the Tri-Gate transistors. Read on to find out it's features, structure and how it benefits the new-age processors.

 

So what comes to your mind when you hear the word 'Intel'? Definitely, a manufacturer of all your celeron's, pentium's, dual cores, core i's, and other micro-processor chips, right? The pace dictated by Moore's Law has required numerous innovations and as a result of which the 'Sponsors of Tomorrow' introduced a three dimensional transistor technology, which is basically, Tri-Gate transistors on its 22 nm logic technology.

Important Turning Point in Transistor Technology
In 1947, the first transistor was demonstrated at Bell Laboratories. Silicon was first used to produce bipolar transistors in 1954, but it was not until 1960 that the first silicon metal oxide semiconductor field-effect transistor (MOSFET) was built. The earliest MOSFETs were 2D planar devices with current flowing along the surface of the silicon under the gate. The basic structure of MOSFET devices has remained substantially unchanged for over 50 years.

Continued optimization and manufacturability studies on 3-D transistor structures was on at research and development organizations in leading semiconductor companies. Some of the process and patent development has been published and publicly shared, and some remained in corporate labs. The International Technology Roadmap for Semiconductors (ITRS) drives the research investment interests of the semiconductor industry, which is coordinated and published by a consortium of manufacturers, suppliers, and research institutes.

The ITRS defines transistor technology requirements to achieve continued improvement in performance, power, and density along with options which should be explored to achieve the goals. The ITRS and its public documentation captures conclusions and recommendations regarding manufacturing capabilities like strained silicon and High-K metal gate, and now the use of 3-D transistor technologies to maintain the benefits of Moore’s law. Based on documents produced by the ITRS and an examination of academic papers and patent filings, research into 3-D transistor technologies has grown dramatically in the last decade.

The Triggers That Threw Spotlight on 3-D Transistors
Two important pronouncements that have occurred in the last two years that have propelled the 3-D transistor structure into the industry spotlight, and into a permanent place in the technology story of MOSFET transistors are 1) The first announcement by Intel Corporation on 4th of May, 2011, about their Tri-Gate transistor design that had been selected for the design and manufacture of their 22 nm semiconductor products. 2) The second announcement was the publication of ITRS technology roadmaps, with contributions from many other semiconductor manufacturing companies that identified 3-D transistor technology as the primary enabler of all incremental semiconductor improvement beyond the 20 nm or 22 nm design node.

So Exactly How Small is 20 nano-meter?
Each and every micro-processor manufactured today is made of millions, or even billions, of tiny electrical components called transistors. Over time, in accordance with Moore's law, transistors have been getting smaller and smaller and because of which, computing and communication devices continue to get smarter, faster and highly efficient.

Intel believes that keeping up with Moore's Law has never been exactly easy. Especially for 22 nanometers, Intel claims that it became clear early on that continued shrinking was not going to give the expected benefits without some radical redesign. After a decade of research and development, taking advantage of the work of Hisamoto and others in FinFET development and optimization, Intel invented the solution. For the first time in history, the transistor has officially entered the 3rd dimension. Image 1 shows what a 3D transistor looks like.

Image 1: A 3D transistor chip

In fact, there are more than a billion transistors on this single chip which, unfortunately, are far too small to be seen with the naked eye. Now imagine yourself 20,000 times smaller! To give you a point of reference, right now, you are even smaller than a human hair. But you would actually still be far too large when compared to a 22 nano-meter transistor for a meaningful imagination. You actually need to be 100 nano-meters tall or about 20 million times smaller than your actual size. At this scale, you are about the right size to literally see, demonstrate some of the attributes and functions of a single, modern transistor out of those millions of transistors inside the 3D transistor chip. Well, since there's no such shrinking device as yet, let us just consider the figures below as transistors models and understand.

But first, what are 2-D transistors?

Image 2: Traditional Planar 2-D Transistor

For the last four decades, planar or 2-D transistors, have been at the core of transistor design and architecture. In the image-2, we see a form of silicon that creates a stream (dotted yellow) through which electrons flow. The gate, which is made of metal over a material with high dielectric constant, controls the flow of electricity in that stream. It acts as an ordinary switch, turning flow on and off. That is, if an ordinary switch had the ability to turn itself on and off over 100 billion times a second! Technically, traditional 2-D planar transistors form a conducting channel in the silicon region under the gate electrode when in the “on” state. Talking about states, some key objectives in transistor design are to have as much current flowing as possible when in the “on state” for performance, to have as close to zero current flowing when it is in the “off” state to minimize power usage, and to switch very quickly between the two states again, for performance.

Now Coming to 3-D Transistors...

Image 3: 22nm Trigate Transistor

As transistors get ever smaller, one way to achieve this is to get tighter control, by having the gate wrap around the channel as much as possible. The animated version of the transistor can be seen in image-3. With Intel's 3D transistor's architecture, the flat two dimensional stream has been replaced with one or more three-dimensional fins as shown in the image-4.

Image 4: 22nm Trigate Transistor

The control is on all the three sides of each fin, rather than just one, as in the the Planar 2-D transistor. In simpler terms, the transistor channel is raised into the 3rd dimension. Current flow is controlled on three sides of the channel (top,left and right). This is called a Tri-Gate transistor and its real advantage over Planar is the ability to operate at lower voltage with lower leakage, providing an unprecedented combination of improved performance and energy efficiency. This breakthrough invention allows Intel to create transistors that are smaller, faster and use less power than ever before, enabling a new generation of computing technology in every category, from the fastest super computers to the smallest hand-held devices. Tri-Gate transistors can have multiple fins (as shown in image 5) connected together to increase total drive strength for higher performance.

Image 5: Tri-Gate transistors with multiple fins

The Real Deal With 3D
The 3-D geometry and structure of the Tri-Gate transistor provides a host of important improvements over the planar transistor structure, all related to the ‘wrap-around’ effect of the MOSFET ‘gate’ around the source-to-drain ‘channel.’ These advantages manifest in improved performance, reduced active and leakage power, transistor design density, and a reduction in transistor susceptibility to charged particle single event upsets (SEU).

The power advantage results from the improved control of the channel by the gate’s electric field on three sides of the fin. As explained by Intel Corporation at their Intel Developer Forums (2011, 2012), this power advantage is created by an effectively steeper transistor voltage curve for Tri-Gate transistors. Transistor designers can take advantage of this steeper curve with either a significant reduction in leakage current for the same performance of a planar transistor, or substantially higher performance (transistor operation speed), or a combination of both.

The Real Advantage of Tri-Gate Transistors
·More than 50% power reduction at constant performance.
·37% performance increase at low voltage.
·Improved performance and efficiency.

"For years we have seen limits to how small transistors can get," said Gordon E. Moore. "This change in the basic structure is a truly revolutionary approach, and one that should allow Moore's Law, and the historic pace of innovation, to continue." - Gordon E. Moore

"The performance gains and power savings of Intel's unique 3-D Tri-Gate transistors are like nothing we've seen before. This milestone is going further than simply keeping up with Moore's Law. The low-voltage and low-power benefits far exceed what we typically see from one process generation to the next. It will give product designers the flexibility to make current devices smarter and wholly new ones possible. We believe this breakthrough will extend Intel's lead even further over the rest of the semiconductor industry." - Mark Bohr, Intel Senior Fellow

FUN FACTS: EXACTLY HOW SMALL (AND COOL) IS 22 NANOMETERS?

The original transistor built by Bell Labs in 1947 was large enough that it was pieced together by hand. By contrast, more than 100 million 22nm tri-gate transistors could fit onto the head of a pin*. More than 6 million 22nm tri-gate transistors could fit in the period# at the end of this sentence. A 22nm tri-gate transistor's gates that are so small, you could fit more than 4000 of them across the width of a human hair^. If a typical house shrunk as transistors have, you would not be able to see a house without a microscope. To see a 22nm feature with the naked eye, you would have to enlarge a chip to be larger than a house. (4) Compared to Intel's first microprocessor, the 4004, introduced in 1971, a 22nm CPU runs over 4000 times as fast and each transistor uses about 5000 times less energy. The price per transistor has dropped by a factor of about 50,000. A 22nm transistor can switch on and off well over 100 billion times in one second. It would take you around 2000 years to flick a light switch on and off that many times**. It's one thing to design a tri-gate transistor but quite another to get it into high volume manufacturing. Intel's factories produce over 5 billion transistors every second. That's 150,000,000,000,000,000 transistors per year, the equivalent of over 20 million transistors for every man, woman and child on earth. *A pin head is about 1.5 mm in diameter. #A period is estimated to be 1/10 square millimeter in area. ^A human hair is about 90 microns in diameter. (4)The smallest feature visible to the naked eye is 40 microns. **Assumes a person can flick a light switch on and off 150 times per minute. Table Courtesy – Intel's Press Material on 22 nm 3-D transistor technology

Tri-Gate Devices Now in Production

Image 6: 22nm Manufacturing Fabs

The advanced state of semiconductor manufacturing at very small geometries (40 nm, 28 nm, 22 nm or 20 nm and beyond) requires research and development expenditures that now limit this technology to a handful of companies with capital expenditure capabilities in the billions of dollars. As a result, only a handful of manufacturers are able to capitalize on the known advantages of 3-D transistor technology. Intel Corporation is the only company to have made this design and manufacturing transition in 22 nm technology, and can provide data on the overall maturity and manufacturability of Tri-Gate transistors on a mass production scale. This data, as of the first quarter of 2013, includes 100 million units of Tri-Gate transistorbased products.

Image 7: Gates and Fins of 22 nm 3-D transistor

Several known issues and characteristics of the 3-D gate structure have been acknowledged and addressed to achieve manufacturing and design maturity with the technology. These include the modeling of new parasitic capacitance values not modeled in traditional planar designs, layout dependent effects, and the use of double-patterning techniques using current lithographic equipment to form closely spaced fins. A great deal of publicity and user education is underway in 2013 by companies like Cadence and Synopsys revolving around the impact of Tri-Gate rules and flexibility in the design of future semiconductor products.

Impact on FPGA and Other Semiconductor Device Performance
Let's see how this three dimensional technology will provide a significant boost in the capabilities of high-performance programmable logic.

The primary advantage of Tri-Gate technology to FPGA-based electronic product designer is the continuation of Moore’s Law in the steady march of improvements in transistor density, performance, power, and cost-per-transistor. This sustains an industry of consumer electronics, computing platform development, software complexity advances, memory and storage growth, mobile device creativity and development, and business automation and productivity.In addition, control over the static and active power dissipation of semiconductors improves tremendously with this technology. For users of FPGAs, this makes programmable logic that advances to 14 nm technology and beyond both power competitive with ASIC and ASSP design solutions on available competing design nodes, with even more significant advantages in programmability, performance, flexibility, Open Computing Language (OpenCL™) software design entry, and integration of DSP, transceiver, hardened processor, and configurable I/Os.
 

Rooftop Solar Plants a Viable Business Opportunity.

Rooftop Solar Plants a Viable Business Opportunity.

Solar rooftop installations are a good investment option considering both tangible and intangible benefits.

  For organisations planning to shift from conventional energy to solar power use, a rooftop solar photovoltaic (PV) power plant can not only be a money saver but also money spinner with excess power supplied to the utility grid. While the Ministry of New and Renewable Energy (MNRE) is still in the process of laying down specificationsfor incentives, experts feel that with the right policies and execution, solar rooftop installations can be a hot trend in green technology. It is a profitabl business concept, and hence a viable investment option.

Installation and Requirements
When solar PV modules are installed on a building’s rooftop to generate solar power, it is called a rooftop power plant. Rooftop PV installation can either be done for standalone use or to feed into the grid.

Some of the factors to consider before installing a solar power plant on your building’s rooftop include electrical load, current rate, roof size, load capacity and geographic location of the building. The subsidy given by the central and state governments, local utilities, and local community regulations and incentives are also some key determinants in the evaluation.

Rooftop solar arrays are best installed on a large and flatroof where direct sunlight without shadow from the surrounding structures is available. If there is shadow on a part of the terrace during the day, PV solar panels are unable to harvest the sun’s energy for that period of time. Let us look at the key considerations while evaluating solar rooftop options.

First, it is important to have a basic understanding of the components of a solar power system and how these generate electricity. PV solar power systems are very simple electric power generating systems comprising the following basic components:

1. A set of PV panels that convert sunlight (photons) into direct-current (DC) electricity
2. A racking system that firml holds the panels to the roof, exposing these to the sun at an advantageous angle
3. Inverters that convert DC electricity into alternating current (AC) electricity
4. Wiring that connects everything
5. A storage battery (in the case of a grid-fed power plant, a large-sized battery is not necessary to store and use that power after sunset)
6. A variety of means to tilt the panels toward the sun to generate more electricity
7. Energy meters to record the en-ergy that is supplied to the grid
8. Junction boxes
9. Earthing kits

Currently, commercially available silicon-based solar PV panels are made from solar cells encased in a special type of toughened glass. Silicon solar modules have been in the fieldfor more than 50 years and perform quite predictably. These are guaranteed for 25 years of feld life but the power yield drops about 0.6 per cent a year. One can use monocrystalline (made from a single crystal) or polycrystalline (made from multiple crystals) panels. Monocrystalline panels are a little more efficientbut the cost per watt is almost the same.

How to supply solar power to the grid?

If the solar power generated from a rooftop installation is to be injected into the grid, one needs to enter into a power purchase agreement (PPA) with the local distribution utility in whose area the solar system is located. Under this agreement, a tariff is determined by the appropriate State Electricity Regulatory Commission (SERC). However, the issues related to grid integration, metering, measurement and energy accounting for projects are under consideration with the government. There is no cost involved in the transmission of energy unless the power is transmitted at high tension (HT) levels (11 kV or 33 kV), and special monitoring and metering hardware are deployed at HT levels. In the current scenario, metering arrangements for rooftop grid-interactive power plants are under active consideration by the government. While no special arrangements are required to inject power into the grid, there is a safety aspect that needs to be factored in while transmitting energy. There is always a risk involved, as when the grid fails the solar power system automatically stops injecting power into the grid. This is called islanding, where the inverter isolates itself. This is a standard feature built into solar power inverters, making these safe for residential and commercial applications. A standalone feature in the inverter would enable captive consumption of the solar power generated in the event of any grid outage.

Copper-indium gallium-diselenide (CIGS) panels may become the preferred type for commercial rooftop projects in another fiveyears. These have the potential to deliver reasonable efficienciesat a lower cost than traditional crystalline panels. However, the cost per watt may not necessarily go down, only the panel size per watt may drop. Today, solar panels (depending on the brand) are bankable, that is, banks loan capital for their purchase.

The solar energy can be used for captive consumption or exported to the grid. The electrical energy (DC) or the solar power generated by the solar PV modules during the sunshine hours is stored in the batteries for use, as and when required. The energy stored in the batteries is converted into 230V AC mains using an inverter. This energy automatically synchronises with the grid and gets injected into it.

Installation by integrators
Many solar system installers and owners have had good experience in anchoring the panel structures. This has to be done scientificallyand with care. It is possible to have non-anchored installation systems but these need to be very carefully designed to with-stand heavy winds. Such systems are designed to connect the solar power system to a roof using weights, rather than fasteners that must be anchored to the roof.

Solar installation companies, often called integrators, can complete a small rooftop project within a few weeks. Before signing a contract with an integrator, evaluate the roof for solar installation with respect to:

Roof condition. The roof should be in a good state prior to solar installation. If it needs significantrepair or replacement, get this done before installing the solar array.

Space availability. Solar power projects work best on flat roofs without obstructions.

Weight load. Some roofs are not designed to hold much additional weight. Ascertain the acceptable weight you can add to your roof before signing a contract.

Investments involved
Of all the components of a solar PV plant, solar module accounts for the biggest cost—it can be 70 per cent of the total project cost. The cost per watt is currently Rs 130-150 ex-factory. The investment primarily depends upon the size of the power plant, which varies from a small kilowatt to multi-megawatt plant. At present, good-quality off-grid rooftop solar power plants can be installed at a cost of Rs 250,000 per kW.

Under the National Solar Mission policy, the benchmark price for an off-grid system is Rs 270,000 per kW peak. For a grid-connected system, it is Rs 190,000 per kW peak. The government also provides a 30 per cent subsidy on the benchmark price. Installation costs would differ in case of remote installations and poor site conditions.

Economic advantages
The total investment per kW in a small power plant, for example, 10kW, will be the same if not less than in a large 5MW plant. It is therefore viable to go for small grid-fed plants owned by small privately-owned utilities. A buying rate of Rs 17 or 18 per unit of electricity from such plants will attract thousands of small investors like a magnet. In most areas in India, solar power can then be a fiscallysound investment that reduces electricity payments immediately, as well as hedges the small solar plant owners against local utility price increases.

If solar power is fed into a small city grid like Miraj, Ratnagiri or Ratlam, all consumers in that area will get cleaner uninterrupted power from the local copper grid. The high impedance of the local grid helps power to remain local, improving the local power quality. That’s why all other countries in the world allow solar plant owners to feed power into the local grid at the low voltage end.

It therefore makes sense to set up a solar rooftop plant in cities or towns facing severe electricity shortages. Today, the cost of generating electricity using a diesel generation (DG) set is in the range of Rs 20-22 per unit, whereas generating solar power costs only Rs 13-15 per unit.

Based on the current prices and assuming that one takes advantage of the 80 per cent depreciation permitted on such investments, in the firstyear the cost of power per unit (kWh) from a well-maintained solar plant will be less than Rs 8 per watt for a plant of any capacity between 5 kW and 1 MW. Thus solar rooftop installation is a good investment option considering both tangible and intangible benefits.

Eligibility criteria for project proponent

While the government is yet to announce the policy for rooftop grid-connected power plants, it has laid down certain guidelines for rooftop PV and other small solar power plants connected to distribution networks at voltage levels below 33 kV. Hereinafter, the programme is referred to as Rooftop PV & Small Solar Power Generation Programme (RPSSGP). Technical criteria. The project schemes that propose to deploy PV modules and inverter systems are considered to be technically qualified and eligible for participation in the RPSSGP scheme only if these comply with relevant IEC/BIS standards and/or applicable standards as specified by the Central Electricity Authority (CEA). For solar PV projects to be selected under this scheme, it is mandatory that these are based on crystalline silicon technology and use modules manufactured in India. There will be no mandatory domestic content requirement for projects based on other technologies. For solar thermal technology, it is mandatory that the technology is demonstrated and such projects should be operational for one year. Project proponents should submit documentary evidence and an undertaking in this regard along with their applications to the competent authority in the state. Metering arrangements. Metering arrangements should be made by the project proponents in consultation with the distribution utility keeping in view the guidelines or regulations notified by the respective state electricity regulatory commissions, if any. Meters should comply with the requirements of CEA regulations on the meter installation and operation. Financial criteria. The project proponents should submit their letters of commitment along with board resolution for equity investments in the project, calculated on the basis of Rs 40 million per megawatt on a pro-rata basis. Infrastructure criteria for land requirement. The project proponents should make arrangements for land required for the project as per conditions outlined by respective state competent authority. Infrastructure criteria for grid connectivity requirement. The plant should be designed for interconnection with the grid at the distribution network at the voltage level depending on the installed capacity of the rooftop PV or small solar system generator. (For the complete requirement list please visit www.mnre.gov.in)

The government is also encouraging the use of rooftop power plants as a substitute for diesel-consuming and polluting DG sets. Most commercial buildings are dependent on diesel generators during power cuts. Investing in a rooftop solar power plant can offset diesel consumption and make the returns attractive. Added to this, the 30 per cent central finance assistance (CFA) in the form of capital subsidy would encourage investors. With a rooftop installation, one can recover the project’s cost within five t six years. Also, typically, a solar power plant has a life of 25 years with proper maintenance.

The return on investment (ROI) completely depends on the power purchase agreement signed by the project developer. While earlier the buying rate for power was Rs 17 per unit, today companies are ready to sell it at Rs 11 per unit, making only a marginal profit.Considering the current trend, the power purchase price can be estimated at Rs 13-14, so one can expect ROI within six to seven years.

More benefits for commercial units
Rooftop installation makes more sense for commercial establishments as these can utilise the solar power during peak-load daytime periods, thus saving the money required to set up battery banks. Any amount of power not used can be stored in a battery bank for use at night when energy consumption is the least (about 10 per cent compared to the day).

 

Scientists create nanoscopic data storage using graphene ‘paper’ and electron ‘ink’

Scientists create nanoscopic data storage using graphene ‘paper’ and electron ‘ink’.

Using graphene “paper” and electron “ink,” Danish and Chinese scientists have created one of the tiniest data storage methods ever devised. In the photo above, captured by a scanning transmission electron microscope (STEM), the thickness of the lines — the font size if you will — is just 2-3nm, or about 50,000 times thinner than a human hair. This technique could eventually be used as a means of nanoscale data storage (can you imagine storing the entire Library of Congress on a single gram of graphene?), or to create graphene-based computer circuits.

As you’re probably aware by now, graphene naturally forms into sheets that are just one atom thick. Gaphene, by virtue of being constructed out of carbon atoms, which are rather small, is the world’s thinnest known material. Interacting with a sheet material that is just one atom thick, however, is rather hard; or, in writing terms, it’s hard to find a suitable “ink.” You can use self-assembly (bottom-up), which uses external factors to control exactly where the graphene grows, but it’s very hard to do this repeatedly at an atomic scale without errors. The other option is lithography (top-down), where you start with a sheet of graphene and burn/etch away the pieces that you don’t need — but to do this, you need to focus an energy source, and there are some pesky laws of physics that get in the way when you approach atomic scales. (See: Graphene aerogel is seven times lighter than air, can balance on a blade of grass.)

The solution, according to researchers at the Technical University of Denmark in Roskilde and Tsinghua University in Beijing, is to combine both the top-down and bottom-up approaches. To do this, the researchers first fire high-energy electrons (300 kiloelectron volts) at a sheet of graphene using a scanning transmission electron microscope (STEM), which has a tip that’s just one nanometer in diameter. These electrons have enough energy to break the carbon-carbon bonds, kicking off carbon atoms and leaving dangling bonds. These loose carbon atoms then rejoin in a messy fashion, creating a region of amorphous carbon that looks very different from the surrounding graphene. By drawing lines, letters, and shapes with the STEM, the researchers leave behind a trail of amorphous carbon — which is what you see in the image at the top of the story.

According to the researchers, this technique offers both high resolution and good controllability/repeatability, which in turn could lead to nanoscale writing being used in nanoscopic data storage and electronics. The big problem, of course, is that a STEM is a room-sized piece of equipment — and, at least for the time being, we’re unlikely to invent a small, cheap device that brings graphene paper and electron ink to the mass market. That’s why the hard drive is still top of the heap when it comes to mass storage: The magnetic grains on a hard drive platter might be 50nm across, rather than the 2nm of graphene paper and ink, but a hard drive performs millions of read/write operations per minute — and it’s smaller than a deck of cards. It will be a long time until anything comes close to supplanting the hard drive.

Graphene aerogel is seven times lighter than air, can balance on a blade of grass

Chinese material scientists have created the world’s lightest material: A graphene aerogel that is seven times lighter than air, and 12% lighter than the previous record holder (aerographite). A cubic centimeter of the graphene aerogel weighs just 0.16 milligrams — or, if you’re having a problem conceptualizing that, a cubic meter weighs just 160 grams (5.6 ounces). The graphene aerogel is so light that an cube inch of the stuff can be balanced on a blade of grass, the stamen of a flower, or the fluffy seed head of a dandelion (see pictures below).

Most aerogels are produced using a sol-gel process, where a gel is dehydrated until only the aerogel remains. Some aerogels are also produced using the template  method — aerographite, for example, is created by growing carbon on a lattice (template) of zinc oxide crystals — and then the zinc oxide is removed in an oven, leaving just the carbon aerogel. To create the graphene aerogel, however, researchers at Zhejiang University use a novel freeze-drying method. Basically, it seems like the researchers  create a solution of graphene and carbon nanotubes, pour it into a mold, and then freeze dry it. Freeze drying dehydrates the solution, leaving single-atom-thick layers of graphene, supported by carbon nanotubes. The researchers say that there’s no limit to the size of the container: You could make a mini graphene aerogel using this process, or a meter-cubed aerogel if you wish.

Graphene aerogel, propped up on the stamen of a flower. The cube, which is roughly an inch across, probably weighs less than 5 milligrams.

The end result is an aerogel that weighs just 0.16 milligrams per cubic centimeter, and has truly superb elasticity and absorption. The graphene aerogel can recover completely after more than 90% compression, and absorb up to 900 times its own weight in oil, at a rate of 68.8 grams per second. With these two features combined, lead researcher Gao Chao hopes that the material might be used to mop up oil spills, squeezed to reclaim the oil, and then thrown back in the ocean to mop up more oil. Beyond filtration, graphene aerogel might be used as insulation — or, if it’s as conductive as aerographite (which seems likely), graphene aerogel could enable the creation of lighter, higher-energy-density batteries.

Over the next few pages we’ve compiled some amazing photos of aerogels. Click through if you want to see lumps of carbon balancing on a blade of grass, centimeter-thick slabs of aerogel that can insulate against the blue flame of a Bunsen burner,  or a two-gram piece of aerogel that can hold up a 2.5-kilogram brick

Now a battery made out of wood!.

In an era where it is cool to be environmentally aware, scientists at the University of Maryland have come up with a formula for batteries that can be counted as cool. These batteries have wood as a major element in their formation, besides fiber and sodium, making them sodium powered batteries. Sodium-ion batteries are, incidentally considered less powerful and efficient than their lithium-ion counterparts. That doesn’t however mean that these batteries can’t be useful.

According to the team of these scientists, these wooden batteries might not end up within your smartphone or your laptop or in any other fancy gadget, but they are extremely useful for storing power on a large scale basis, given the fact that they are good for storing electrolytes as they can swell and contract many times over.

The side effect of the process, which will lead to erosion in battery capacity is the fact that the wood wrinkles due to the stress involved, but this doesn’t stop the battery from working, In fact, according to the claims of these scientists, the batteries can be charged and recharged over 400 cycles and have a capacity of 339 mAh/g. This will only increase as the scientists better the design.

Large scale production, however, is still some way off as what has been revealed is a working prototype at best. The discovery, however, does bode well for the future given the fact that, this is, in essence a low cost, environmentally friendly battery tech.

“The inspiration behind the idea comes from the trees. Wood fibers that make up a tree once held mineral-rich water, and so are ideal for storing liquid electrolytes, making them not only the base but an active part of the battery,” says Hu, an assistant professor of materials science, at the University.

E-waste Management In India

E-waste Management In India.

You are welcome to change your personal computer, cell phone, refrigerator, or for that matter any electronic or electrical gadget, but be careful while disposing of the old one. Throwing it into the dustbin is not the proper disposal of an electronic equipment which has attained obsolescence as per your judgement. 

It may end up adding to e-waste, which creates problems for the ecology in general and directly or indirectly for the living beings around there through air, water and soil pollution.

The aim of this article is to spread awareness among our readers about the various issues involved in generation and management of e-waste, particularly from Indian perspective.
What is e-waste?
Electronic waste (e-waste) comprises waste electronics/electrical goods that are not fit for their originally intended use or have reached their end of life. This may include items such as computers, servers, mainframes, monitors, CDs, printers, scanners, copiers, calculators, fax machines, battery cells, cellular phones, transceivers, TVs, medical apparatus and electronic components besides white goods such as refrigerators and air-conditioners.

E-waste contains valuable materials such as copper, silver, gold and platinum which could be processed for their recovery.

Is e-waste hazardous?
E-waste is not hazardous per se. However, the hazardous constituents present in the e-waste render it hazardous when such wastes are dismantled and processed, since it is only at this stage that they pose hazard to health and environment.

Electronics and electrical equipment seem efficient and environmentally-friendly, but there are hidden dangers associated with them once these become e-waste. The harmful materials contained

 in electronics products, coupled with the fast rate at which we’re replacing outdated units, pose a real danger to human health if electronics products are not properly processed prior to disposal. Electronics products like computers and cellphones contain a lot of different toxins. For example, cathode ray tubes (CRTs) of computer monitors contain heavy metals such as lead, barium and cadmium, which can be very harmful to health if they enter the water system. These materials can cause damage to the human nervous and respiratory systems. Flame-retardant plastics, used in electronics casings, release particles that can damage human endocrine functions. These are the types of things that can happen when unprocessed e-waste is put directly in landfill.

The scenario
The Basel Action Network (BAN) which works for prevention of globalisation of toxic chemicals has stated in a report that 50 to 80 per cent of e-waste collected by the US is exported to India, China, Pakistan, Taiwan and a number of African countries. This is done be-cause cheaper labour is available for recycling in these countries. And in the US, export of e-waste is legal.
e-waste recycling and disposal in China, India and Pakistan are highly polluting. Of late, China has banned import of e-waste. Export of e-waste by the US is seen as lack of responsibility on the part of Federal Government, electronics industry, consumers, recyclers and local governments towards viable and sustainable options for disposal of e-waste.

In India, recycling of e-waste is almost entirely left to the informal sector, which does not have adequate means to handle either the increasing quantities or certain processes, leading to intolerable risk for human health and the environment.

Dynamics of e-waste generation
Telecommunications and information technology are the fastest growing industries today not only in India but world over. Manufacturers’ Association for Information Technology (MAIT) has collected the following statistics on the growth of electronics and IT equipment in India:
1. PC sales were over 7.3 million units during 2007-08, growing by 16 per cent. There is an installed base of over 25 million units.
2. The consumer electronics market is growing at the rate of 13-15 per cent annually. It has an installed base of 120 million TVs.
3. The cellular subscriber base was up by 96.86 per cent during 2007-08. Its installed base is estimated to cross 300 million mark by 2010.

With the unprecedented induction and growth in the electronics industry, obsolescence rate has also increased. People are phasing out/replacing their IT, communication and consumer electronics equipment including white and brown goods as shown in Table II.

As per a GTZ-MAIT sponsored study conducted recently by IMRB, e-waste generated in India during 2007 was around 332,979 MT besides about 50,000 MT entering the country by way of imports. The reasons for generation of this large quantity of e-waste were unprecedented growth of the IT industry during the last decade, and the early product obsolescence due to continuous innovation. Thus the net effect is the e-waste turning into a fastest growing waste stream.

However, the total e-waste avail-able in 2007 for recycling and re-furbishing was 144,143 MT. Of this, only 19,000 MT of e-waste could be processed.

Components of e-waste management
The major components of e-waste management are:
1. e-waste collection, sorting and transportation
2. e-waste recycling; it involves dismantling, recovery of valuable resource, sale of dismantled parts and export of processed waste for precious metal recovery

The stakeholders, i.e., the people who can help in overcoming the challenges posed by e-waste, are:
1. Manufacturers
2. Users
3. Recyclers
4. Policy makers

e-waste concerns and challenges
1. Accurate figures not available for rapidly increasing e-waste volumes—generated domestically and by imports
2. Low level of awareness among manufacturers and consumers of the hazards of incorrect e-waste disposal
3. No accurate estimates of the quantity of e-waste generated and recycled available in India
4. Major portion of e-waste is processed by the informal (unorganised) sector using rudimentary techniques such as acid leaching and open-air burning, which results in severe environmental damage
5. e-waste workers have little or no knowledge of toxins in e-waste and are exposed to health hazards
6. High-risk backyard recycling operations impact vulnerable social groups like women, children and immigrant labourers
7. Inefficient recycling processes result in substantial losses of material value and resources
8. Cherry-picking by recyclers who recover precious metals (gold, platinum, silver, copper, etc) and improperly dispose of the rest, posing environmental hazards
9. No specific legislation for dealing with e-waste at present
Status of e-waste initiatives
The Ministry of Environment & Forests (MoEF) of the government of India is responsible for environmental legislation and its control. The Central Pollution Control Board (CPCB), an autonomous body under the MoEF, plays an important role in drafting guidelines and advising the MoEF on policy matters regarding environmental issues. Historically, in 2001 in cooperation with MoEF, the German Technology Cooperation (GTZ) began work on hazardous waste management in India through the advisory services in environmental management. Subsequently, Swiss Federal Laboratories for Material Testing and Research (EMPA) started to implement its global programme ‘Knowledge Partnerships in e-waste Recycling.’

Combining the knowledge and technical expertise of EMPA on e-waste management, coupled with the field experience of the Indo-German projects in managing hazardous waste in India, the Indo-German-Swiss e-waste initiative was born in 2004. The vision of this initiative is to establish a clean e-waste channel that is a:
1. Convenient collection and disposal system for large and small consumers to return all their e-waste safely
2. Voluntary system for modern and concerned producers to care for their product beyond its useful life
3. Financially secure system that makes environmentally and socially responsible e-waste recycling viable

The objectives of the initiative are:
1. Reduce the risks to the popula-tion and the pollution of the environ-ment resulting from unsafe handling
2. Focus on knowledge transfer to and skills upgrade of all involved stakeholders through trainings and seminars
3. Target mainly the existing informal recyclers allowing for their maximum but safe participation in future e-waste management by facilitating their evolution and integration in formal structures

The milestones achieved so far are:
1. Improved awareness:
• Three WEEE Care! Initiative workshops in Bangalore sup-ported by the Goethe Institute
• National e-waste workshop in Delhi, hosted by MoEF

2. Improved stakeholder engage-ment:
• Formation of the e-waste Agency (EWA) brings together industry, government and NGO to work on a sustainable e-waste management strategy for Bangalore
• First national e-waste workshop held, defined a way forward
• First national workshop on e-waste guidelines held, organised by MoEF

3. Improved estimates of e-waste:
• Rapid assessments in Delhi and Bangalore of the quantities being generated, and identification of the e-waste recycling hot-spots
• National-level desk study to assess e-waste quantities

A national-level assessment of electronics and electrical equipment waste (WEEE) by MoEF/CPCB/IRG/GTZ lists the top ten most polluting states and cities of India as shown in Tables III and IV. The figure are taken from the presentation of Dr Dilip B. Boralkar at National Conference on E-Waste Management, an Indo-German-Swiss E-Waste Initiative, at New Delhi on December 10, 2008.

The MAIT-GTZ study on e-waste found that 94 per cent of the organisations studied did not have any policy on disposal of obsolete IT products. Though many respondents (200 corporates and 400 households) were aware of e-waste, they were lacking in action.

Vinnie Mehta, executive director of the MAIT, in his presentation at National Conference on E-Waste Management (an Indo-German-Swiss E-Waste Initiative), listed the following legislations that cover different aspects of e-waste:
1. The hazardous waste (management and handling) rules, 1998 as amended in 2008 for toxic content—registration mandatory for recyclers
2. Municipal solid waste management and handling rules for non-toxic content
3. Basel convention for regulating trans-boundary movement
4. Foreign trade policy, which restricts import of second-hand computers and does not permit import of e-waste
5. Guidelines by Central Pollution Control Board (2008)

The guidelines notified in April 2008 identify and recognise:
1. Producers’ responsibility
2. RoHS (restriction on hazardous substances)
3. Best practices
4. Insight into technologies for various levels of recycling

Mehta said that the guidelines explicitly mention the need for a separate legislation for implementing producers’ responsibility. He said that e-waste is ‘distinct’ as it is an end-of-consumption waste while hazardous waste results from a distinct industrial process. The Environment Protection Act provides for separate regulations for waste with ‘distinct’ characteristics—Biomedical Wastes (M&H) Rules 1998, Batteries (M&H) Rules 2001, etc.

Advocating a separate legislation for e-waste, he said that in his recent presentation to members of the parliament he has emphasised that e-waste value chain is rather complex as it involves multiple players—producers, distributors, retailers, end consumers, collection system and recyclers—while hazardous waste chain involves only the occupier/generator and the operator. Recovery of non-ferrous metals and reprocessing of used oil are the only two major activities in hazardous waste recycling, while e-waste recycling involves refurbishment for reuse, dismantling and precious metal recovery, which is a complex process.

Structure of the Proposed e-Waste Legislations

1. Title: E-waste (Management & Handling) Rules to be published under the Environment Protection Act 2. Objective: To put in place an effective mechanism to regulate the generation, collection, storage, transportation, import, export, environmentally sound recycling, treatment and disposal of e-waste. This includes refurbishment, collection system and producer’s responsibility, thereby reducing the wastes destined for final disposal. 3. Essence: The producer of electrical and electronic equipment is responsible for the entire life cycle of its own branded product and in particular the environmentally sound end-of-life management and facilitating collection and take back. 4. Responsibility of each element in the e-waste value chain: • Producers • Dealers • Collection agencies/collection Centres • Dismantlers • Recyclers • Consumer and bulk consumers 5. Procedure for authorisation of producers, collection agencies, dismantlers, recyclers and enforcement agencies 6. Procedure for registration/renewal of registration of recyclers 7. Regulations for import of e-waste 8. Liability of producers, collection agencies, transporters, dismantlers and recyclers 9. Information & tracking 10. Elimination of hazardous substances used in e-equipment 11. Setting up of designated authority to ensure transparency, audit and inspect facilities, examine authorisation/registration, etc

e-nam (EWA Newsletter for Awareness and Management) in its September 2008 issue has brought out the latest activities of EWA, MAIT-GTZ and others involved in the e-waste field. It has published extracts of an article titled ‘Progress on e-waste, but Too Slow’ by Mini Josheph Tejaswi. The statements of various experts quoted in the article are reproduced below:

Lakshmi Raghupathy, former director in the ministry of environment and forest and an expert in e-waste management, said that governmental regulations should make the producers solely responsible for the entire life-cycle—from manufacturing to recycling—of their products.

Nitin Gupta, CEO of Attero Recycling, said enterprises should be extremely careful and responsible while throwing their unwanted computers and storage devices.

Computer manufacturers in India are slowly getting active in e-waste management. “We are working with all stakeholders in the e-waste management eco-system,” said S. Shankar, director (manufacturing and supply chain) in HP. The company has initiated a three-pronged strategy: partner with e-waste recyclers, build awareness among individual/enterprise customers and work with NGOs, recyclers, collectors and dismantlers.

Anne Cheong, senior service specialist in Dell, said each manufacturer has an individual producer responsibility. “We start from home. We have proper recycling facility in all countries including India. We are exploring that in Karnataka as well.”

Though companies claim they are taking action, many don’t believe enough is being done. “Things are very slow. Corporates are yet to understand the importance of it,” said Wilma Rodrigues, founder member of Saahas, a development organisation. Decisions related to e-waste management, she said, are still taken by junior employees in organisations, with top executives not even looking at it. Almost every company has some mention on its website on e-waste management, but very few are doing anything. The country has twelve authorised e-waste recyclers including e-Parisara and Ash in Bangalore, Tessam in Chennai and Eco-Reco in Mumbai. Ramky Group is setting up the country’s largest integrated e-waste management facility in Bangalore in collaboration with GTZ, while Attero is building an integrated e-waste recycling plant in Utter Pradesh.

D.C. Sharma, vice president of Ramky Enviro Engineers, cautioned that no player should indulge in cherry-picking, collect whatever one thinks is worth and leave the hazardous portions out. Ramky is also building a transfer storage disposal facility (landfill) for hazardous waste at Dobbespet on Tumkur Road.

Finally, through improved e-waste management in the major Indian cities, the e-waste initiatives taken in the country will achieve better environ-mental conditions. Moreover, health conditions of workers active in the e-waste recycling sector will enormously improve at the local level. As an overall effect, the living conditions for the neighbouring population will be better. The already existing schemes of e-waste recycling and material recovery, mainly in the informal sector, will be transformed to transparent and workers- and environment-friendly methods. In the long term, the problem of improper e-waste recycling will disappear due to improved methods, implementation of a take-back system and consideration of the extended producer’s responsibility.

Experience exchange on national and international levels, including know-how transfer, is being facilitated through the various initiatives. Thus, a dialogue platform for Indian and European e-waste experts has been created, opening the doors for future industries to be developed and cooperation activities to be per-formed for technology and knowledge transfer.

Microwave Tubes Making a Comeback

Microwave Tubes Making a Comeback.

Scientists are looking back at the microwave tubes for high-power and high-frequency applications because only these can handle a power of up to 300 megawatts at a frequency of 1 Ghz.

A high-power microwave system consisting of a high-power microwave tube, high-voltage measurement chamber and power conditioning unit

In 1904, J.A. Fleming introduced the vacuum tube diode. After the second world war, electron tubes were used to develop the first generation of computers but these computers were impractical due to the  large sizes of the electronic components. In 1947, John Bardeen, Walter Brattain and William Shockley demonstrated the amplifying action of the firsttransistor at Bell Telephone Laboratories. They received a Nobel Prize for it. 

Bipolar transistors and digital integrated circuits (ICs) were made fist. Analogue ICs, large-scale integration (LSI) and very-large-scale integration (VLSI) followed by the mid-1970s. A VLSI design consists of thousands of circuits on a single chip with transistors acting as on/off switches or gates between them. Transistors are good for low-power and low-frequency applications. Microcomputers, medical equipment, video cameras and communication satellites are all examples of devices made possible by using ICs. 

From the day of invention of vacuum tube till today, when millions of transistors are fabricated on a single chip, technology has advanced a lot. But scientists are looking back at the microwave tubes for high-power and high-frequency applications because only these can handle high power (nearly 300 megawatts) at high frequency (nearly 1 GHz). 

The term ‘microwave’ denotes the techniques and concepts used as well as a range of frequencies. Microwaves travel in matter in the same manner as light waves. These are reflected by metals, absorbed by some dielectric materials and transmitted through other materials without significant losses. 

The helix slows down the propagation of electrons as these travel down the tube. The electrons bunch, and reinforce the voltage in the helix, which creates amplification (Courtesy: Thales Electron Devices)

Many R&D centres in India are actively inrolved in the advancement of microwave tubes. These include:

1. Central Electronics Engineering Research Institute, Pilani
2. Central Scientific Instruments Organisation, Chandigarh
3. Central Glass and Ceramic Research Institute, Kolkata
4. Central Mechanical Engineering Research Institute, Durgapur
5. Bharat Electronics Ltd, Bengaluru
6. Vacuum Electronics Devices and Application Society
7. Microwave Tube Research and Development Center, Bengaluru
8. Center of Research in Microwave Tubes, BHU
9. College of Engineering and Technology, Moradabad
10. Institute of Plasma Research, Gandhinagar
11. Society for Advanced Microwave Electronics Engineering & Research, Mumbai 

Microwave tubes have potential applications in radar, electronic warfare and communication systems. Air-traffic-controlradars, military radars, ground penetrating radars, imaging radars, UWB radars, cloud radars and space debris radars are some types of radars that use microwave tubes. Multi-beam jammers, phase-array jammers, and ultra-high-frequency and ultra-wide-bandwidth jammers used in electronic warfare also use microwave tubes. Clouds can be seen by microwave. These tubes play a role in climate forecasting and some medical applications (used in the diagnosis of hyperthermia) as well. Besides, microwave has its utilities for common man in the form of microwave heating and microwave protective gear/wall paper/furnishing.


Basic principle of microwave devices

The efficiency of conventional tubes is largely independent of the frequency up to a certain limit. When the frequency increases beyond that limit, several factors combine to rapidly decrease the tube’s efficiency. The high-frequency effects in conventional tubes are circuit reactance (inter-electrode capacitance, lead inductance), transit-time effect, cathode emission, plate-heat dissipation, power loss due to skin effect, radiation and dielectric loss.

Microwave devices

Conventional devices. Klystrons, magnetrons, traveling-wave tubes, backward-wave oscillators and crossed-field amplifiers New-generation devices. Cyclotron resonance devices (gyrotrons, gyro-TWTs and klystron-BWOs), Cerenkov radiation devices (magnetrons/BWOs/TWTs, orotrons, magnetically insulated line oscillators), Doppler effect-based devices (free-electron lasers, ubitrons, cyclotron auto-resonance masers), space-charge devices (virtual cathode oscillators) and multi-beam devices

Tubes that are efficient in the microwave range usually operate on the theory of velocity modulation. The microwave tube uses transit time in the conversion of DC power into radio-frequency power. The interchange of power is obtained by using the principle of electron velocity modulation and low-loss resonant cavities in the microwave tube.

Velocity modulation is define as the variation in the velocity of a beam of electrons caused by the alternate speeding up and slowing down of the electrons beam. This variation is usually caused by a voltage signal applied between the grids through which the beam must pass. The directions of the electron beam and the static electrical field are parallel to linear beam tubes. Against this, the field sinfluencing the electron beam stand vertically by the electron beam at the crossed-field tubes.

Magnetron—a microwave device
Magnetrons are a special form of diodes. Electrons move between the cathode and anode in a curved fashion, and thus the electric field and the magneti field are normal to the electron beam. When an electron is slowed down by an electric or magnetic field, it gives up energy, making the field stronger. If an electron’s speed is increased by an electric or magnetic field, it weakens the field.

An amplifier tube circuit that generates radio frequency signals is called an oscillator. A resonant circuit consisting of an inductor (coil) in parallel with a capacitor determines the frequency and wavelength of the oscillator. The lesser the number of turns in the coil, the smaller the capacitor plates and the higher the radio frequency that the oscillator generates. 

Magnetrons have a central cylindrical cathode surrounded by an anode in the form of a thick cylindrical shell. Top and bottom plates form the remainder of the vacuum envelope. These plates are placed between the poles of a strong magnet.

The controlled resonant circuit problem at microwave frequencies is solved by using hollow metal cylinders as a resonator. The round cylinder walls are similar to a one-turn coil and the cylinder end plates are like a very small capacitor. These cylindrical resonators are called microwave cavities. By moving one of the cavity’s end plates in or out of the cylinder, the frequency of the oscillator can be tuned. The cylinder must be about a wavelength in diameter and about one-half wavelength long at the resonant frequency. Energy can flowin and out of the resonator through a hole in the cylinder wall. 

Future technology

1. Multiple-beam klystrons for synthetic-aperture radars and missile seekers 2. TWTs for towed decoys 3. Microwave power modules based transmit/receive modules for phased-array radars 4. High-power microwave devices for directed-energy weapons 5. Gyro TWTs for radar applications 6. Vacuum microelectronics based microwave devices (TWT on a chip) 7. Tera-hertz devices for secure high-data-rate communication, imaging and radar 8. Microwave power beaming rectennas 9. Microwave propulsion 10. Microwave plasma chemistry 11. Microwave-generated artificial ionospheric mirrors (over-the-horizon radars and battlefield illumination)

The microwave fields from the resonators extend into the region between the cathode and anode. A strong magnetic field makes the highspeed electrons move such that these don’t reach the anode and return to the cathode, unless slowed down by giving up energy to a cavity electric field.

If the electrons arrive at the wrong time, these take energy from the microwave field, speed up and spiral back t the cathode. At the correct voltage and microwave frequency, the electrons move at the correct velocity to continue to loose speed and give up most of the energy to the microwave field before the impact on the anode. 

Other devices

Magnetron oscillator was the first device developed that was capable of generating large powers at microwave frequencies. Later, improved devices such as travelling-wave tube amplifiers (TWTAs) were developed for use in microwave systems. Yet, magnetron production continues for use in micro-wave ovens. 

Cross-field amplifier (CFA) is another microwave power amplifier. It is a cross between TWTs and magnetrons in its operation. It has a magnetron structure to provide interaction between crossed DC electric and magnetic fieldson one hand and RF field on he other. It also uses a slow-wave structure, as in TWT, to provide a continuous interaction between the electron beam and a moving RF field.

The backward-wave oscillator (BWO) is also a microwave-frequency and velocity-modulated tube that operates on the same principle as the TWT. However, a travelling wave that moves from the electron gun end of the tube towards the collector is not used in the BWO. Instead, the BWO extracts energy from the electron beam using a backward wave that travels from the collector towards the electron gun (cathode).